This Core component of the Center will provide essential central shared resources to all components; these include medical, psychiatric assessment, computer, statistical, subject recruiting, pharmacy, urinalysis, secretarial, and administrative support services. These resources will permit the conduct of controlled experiments described in the other components by supporting recruitment, screening, intake, and psychiatric/behavioral characterization of study participants; medical evaluation and supervision of participants; pharmacy preparation of appropriately-blinded medications; collection of clinical outcome data (both urinalysis results and clinical interview/assessment results); management and analysis of study data; and scientific reporting of Center results. This application builds on an existing sophisticated research program that is well-experienced and productive in all of these domains. These Core resources will permit us to obtain important data concerning how best to implement LAAM pharmacotherapy of opioid abuse and concerning the effective implementation of structured behavioral therapies for drug abuse. The studies will be conducted in three sites -- a well-controlled residential human laboratory, an outpatient clinical pharmacology treatment research clinic, and a community drug abuse treatment clinic. At all sites the psychiatric assessment staff will provide careful psychiatric diagnostic and behavioral screening and characterization of the participants. These assessment data will be used to stratify the randomization of participants in the clinical trials and to identify patient characteristics associated with variations in outcome. Of greatest interest will be comparisons of patients with and without antisocial personality disorder and the possibility of their differential response to treatment conditions, especially to the structured behavioral interventions to be studied in the community treatment clinic. Antisocial drug abusers are of special interest because they are prevalent, difficult to treat, and have elevated rates of HIV risk behavior and HIV infection. These Center assessment data will provide valuable information about the relation of individual patient characteristics to drug abuse treatment outcome, and about how best to identify and assess for treatment-relevant differences in individual patient characteristics. Overall, these Core resources and data should contribute to improvements in LAAM pharmacotherapy and in behavioral therapy, and to improved bases for patient-treatment matching.